MLB, the NHL and several soccer leagues have signed prediction market partners while nine states dispute whether the contracts are legal. Every deal includes a clause voiding it if courts side against the platforms. Only the NFL is holding out. Will it outlast the rush to sign first?
The leagues are not waiting for the courts to decide whether prediction markets are legal. Kalshi’s claim to federal jurisdiction is tested in nine states (see ”The Legal War”), but commissioners are signing with prediction markets anyway, locking in data rights and broadcast exposure now and writing the insurance in afterward.
Every agreement carries the same clause: void if a court eventually rules that event contracts on sports outcomes are unlawful gambling. Polymarket has signed more leagues, Kalshi taken in more revenue. At any rate, the two platforms are in essence selling commissioners’ offices the same thing twice.
The exemplar – baseball
MLB’s is the deal worth reading in full, because it’s the only one that goes beyond a commercial handshake. Announced March 19, it named Polymarket the league’s exclusive prediction-market partner at a reported value of $150 million to $300 million ($150m–$300m) over three years. The top of that range is an estimate by the press, not a figure MLB has confirmed (Front Office Sports).
Commissioner Rob Manfred signed something rarer alongside it: a memorandum of understanding directly with the CFTC and its chairman, Michael Selig. It was the first such agreement between the regulator and a major American sports league, committing both sides to regular consultation on integrity threats (MLB.com). The commercial deal restricts markets on things like individual pitches, manager decisions, and umpire performance. It also requires Polymarket to write those restrictions into its US rulebook, so that every broker is held to them.
Sportico at the time flagged a problem: the rulebook changes and the MOU bind Polymarket’s regulated US exchange, not the much larger offshore platform that most of its volume still runs through.
Outside the MLB
Polymarket built the rest of its roster on the same template without the CFTC layer. TKO Group Holdings signed a multiyear UFC exclusive. LaLiga followed on April 2, brokered by Relevent for the US and Canada. Then came Serie A and Liga MX, as regional US partnerships. On June 22 the Bundesliga signed a deal for the 2026/27 season, again through Relevent, which holds the German league’s Americas commercial rights across 35 markets (crypto.news).
Major League Soccer’s version, agreed to in January, is the one structurally different case. Polymarket became the league’s first Authorized Prediction Market (APM). By the designation’s terms, MLS holds approval rights over which contracts get listed at all. It’s more than a monitor after the fact (Sportico).
The NHL’s deal makes the thesis literal. In October 2025 it signed with Kalshi and Polymarket on the same day, making them joint official partners rather than picking one. Both receive identical data, marks and broadcast signage (NHL.com). The NHL has also gone furthest to turn integrity terms into a working system: months of list-building with the integrity firm IC360 have let both platforms block athletes, officials and league employees preemptively from trading in associated markets (crypto.news).
Kalshi’s own list is shorter and points a different direction. Its one major team deal is the Chicago Blackhawks, signed Dec. 23, 2025, for joint branding and United Center signage. It has in addition smaller partnerships with the Pro Padel League and Baller League. While Polymarket has been buying league rights, Kalshi has been extending its reach. The difference shows up in media deals, not team logos.
The NBA and the NFL sit at opposite ends of the same spectrum. The NBA is in talks with both platforms, a process that has moved faster since Selig’s confirmation as CFTC chairman, with a deal expected before the 2026/27 season. The NFL has no deal and, by its own account, wants none until it gets one.
In a letter sent March 29 through Executive Vice President Jeff Miller and Vice President David Highhill, the league asked both platforms to drop four categories of contract (ESPN):
- outcomes a single person can manipulate, such as a missed field goal
- outcomes knowable in advance, such as draft picks
- anything tied to officiating
- a broader set it called “inherently objectionable,” to include injuries
Selig said the CFTC would give a league’s own manipulation assessment “substantial deference” (USI Gaming Hub), but the letter is an unsigned wish list, not a contract. MLB got its restrictions written into a rulebook by agreeing to a deal first.
The rest of the map
Leagues aside, Kalshi holds a multiyear exclusive with CNBC (this includes a minority investment) as well as data deals with Fox and CNN. Polymarket has Yahoo Finance and Dow Jones, the latter feeding real-time data into the Wall Street Journal, Barron’s and MarketWatch. Google Finance plans to carry both platforms’ odds.
Athletes have joined as investors on each side: Milwaukee’s Giannis Antetokounmpo and Kyle Kuzma with Kalshi, Philadelphia’s Saquon Barkley with Polymarket.
Wealthsimple is preparing to launch an app, Wealthsimple Predict, with Kalshi event contracts in Canada this summer, with sports and election markets excluded under Canadian Investment Regulatory Organization rules.
The outlier
This leaves the NFL as the piece everyone is waiting on. Every league that has signed – MLB most explicitly – has bet that building the void clause into the contract now is cheaper than waiting for the legal war to end. The NFL is still deciding whether to put in its chips.
